A best-selling smartphone app used for measuring blood pressure has been shown to deliver “highly inaccurate” results, according to a study published in the medical journal JAMA Internal Medicine. Although the popular app, known as Instant Blood Pressure (IBP), has accumulated 150,000 downloads, researchers found that the results given were inaccurate 8 out of 10 times.
The finding raises the question of reliability of mobile apps and has summoned calls for regulation of this fast growing sector.
IBP was a bestselling health app on both the Apple and Android app stores, available between June of 2014 and July of 2015 for a price of $4.99. It purports to accurately measure blood pressure by having users place the upper edge of their smartphones on their chest while placing a finger over the built-in camera lens.
Timothy Plante and colleagues at Johns Hopkins tested out the app on 85 participants. More than half of the participants had self-reported hypertension, and 91% reported taking anti-hypertensive medications.
The researchers discovered that the app had a tendency to inform users that their blood pressure was in the normal range when it was actually mucher higher. In general, they found the app underestimated higher blood pressure levels and overestimated lower blood pressure levels.
The authors wrote:
“The low sensitivity for hypertensive measurements means that approximately four-fifths (77.5%) of individuals with hypertensive BP levels will be falsely reassured that their [blood pressure] is in the nonhypertensive range.”
“Our study has both clinical and public health relevance. While IBP recently became unavailable for unclear reasons, it is installed on a vast number of iPhones.”
Ryan Archdeacon, CEO of Auralife, the company behind the app told Fortune:
“We were shocked to have identified critical deficiencies and inaccuracies in the study control design and data analysis that cause it to inaccurately portray the performance of Instant Blood Pressure. We have our own data.”
According to IMS Health – a company that provides information, services and technology for the healthcare industry – there are more than 165,000 mobile health apps available on the market and the m-health sector could be a $26 billion industry by the end of 2017.